PHOTO NO.: STScI-PRC99-14
HUBBLE SHOOTS THE MOON
In a change of venue from peering at the distant universe, NASA's Hubble
Space Telescope has taken a look at Earth's closest neighbor in space,
the Moon. Hubble was aimed at one of the Moon's most dramatic and
photogenic targets, the 58 mile-wide (93 km) impact crater Copernicus.
The image was taken while the Space Telescope Imaging Spectrograph
(STIS) was aimed at a different part of the moon to measure the colors
of sunlight reflected off the Moon. Hubble cannot look at the Sun
directly and so must use reflected light to make measurements of the
Sun's spectrum. Once calibrated by measuring the Sun's spectrum, the
STIS can be used to study how the planets both absorb and reflect
sunlight.
(Not shown)
The Moon is so close to Earth that Hubble would need to take a mosaic of
130 pictures to cover the entire disk. This ground-based picture from Lick
Observatory shows the area covered in Hubble's photomosaic with the Wide
Field Planetary Camera 2.
(STScI-PRC99-14a)
Hubble's crisp bird's-eye view clearly shows the ray pattern of bright
dust ejected out of the crater over one billion years ago, when an
asteroid larger than a mile across slammed into the Moon. Hubble can
resolve features as small as 600 feet across in the terraced walls of
the crater, and the hummock-like blanket of material blasted out by the
meteor impact.
(STScI-PRC99-14b)
A close-up view of Copernicus' terraced walls. Hubble can resolve
features as small as 280 feet across.
Credit: John Caldwell (York University, Ontario), Alex Storrs (STScI),
and NASA